I had it on my Mazda3, it definitely helped. But... after driving on an OS Giken on a Mazdaspeed3... I'd rather spend more money for a diff that works significantly better.

Nothing compares to the OSG clutch diffs, theyíre just outstanding for track purposes. They cost several times the product in question, and still about twice as much as a Wavetrac.

The company in question is new to BMW, but not at all new to limited slips. Product seems quality but why not let the group buy folks see how they like theirs. Should have a good number of products on the road in the next month or two. If reviews are good Iíll be buying one for sure, $1K for a proper limited slip is too good a deal to pass up.

i still dont understand how everyone is really worried about like $200-$300 difference in product that is total probably $2500 for all work including install when it would be much more costly later down the road if it broke.

if you going with helical why not spend the money for the quaife and not worry about much? now if this thing was different and had some special feature and was cheaper that they guarantee then I might consider but there is only so much you can do with helical type.

if you cant afford $300 then this car might not be the car you should be modifying.

i still dont understand how everyone is really worried about like $200-$300 difference in product that is total probably $2500 for all work including install when it would be much more costly later down the road if it broke.

if you going with helical why not spend the money for the quaife and not worry about much?

if you cant afford $300 then this car might not be the car you should be modifying.

Fair point. For me itís just a matter of value, the absolute cost isnít what sways me one way or the other. My car is not tracked, so a limited slip is of limited value (no pun intended). As such, price savings are going to be the only thing that drives me to buy one, since itís just not necessary.

I agree with your point though, generally speaking. $800 for an LSD is a very reasonable price however. This company has an established background in clutch based racing diffs, they appear to be a quality outfit.

i still dont understand how everyone is really worried about like $200-$300 difference in product that is total probably $2500 for all work including install when it would be much more costly later down the road if it broke.

if you going with helical why not spend the money for the quaife and not worry about much? now if this thing was different and had some special feature and was cheaper that they guarantee then I might consider but there is only so much you can do with helical type.

if you cant afford $300 then this car might not be the car you should be modifying.

OP get what you want it's your car! Just makes sure you research and do your homework. If you can live with the short-falls if there are any then get it.

I'm paying like $1000 for all this including the front suspension, hubs and brakes. I just need to get a prop made up - simple enough.

Keep us updated, i'd be interested in this down the road on my E90.

An E8x member tried this on his 1, can't recall what the deal was but I think it ended up being a serious PITA. I want to say the subframe is what didn't play nice, but obviously this is a cleaner swap E9x to E9x.

I have experience with them. Have it on a kswap honda. They are really great for the money. Plus they now have a better guarantee on their products compared to other companies. Ive ridden ib other kswap vehicles with a qualfie and in all honesty you are just paying for the name for increase in price imho. But nevee had a hickup with this lsd looking forward to getting one for my e92. I used my car for a daily and some spirited runs.

I fitted the M Factory Helical LSD to my E92 335i 2 weeks ago and so far so good. It took me 5 hrs start to finish to fit (bolted diff), and was really straightforward.
As for the difference it is night and day. The car no longer struggles for traction and it makes for miles more fun in the corners! Its also very quiet, probably more so than the factory diff.
I had a Quaife lsd fitted to my older E90 330D (still 320Bhp/700+ Nm) and I have to say the M factory is superior; Overall the car is miles more predictable!
I didn't make my decision based on price either, Just was disappointed with my Quaife last time and fancied a change and had been recommended the M factory from a couple of guys I know who race hondas.

I do not work for of have any affiliation with M-factory and realise the mistake in this being my 1st post!!

I fitted the M Factory Helical LSD to my E92 335i 2 weeks ago and so far so good. It took me 5 hrs start to finish to fit (bolted diff), and was really straightforward.
As for the difference it is night and day. The car no longer struggles for traction and it makes for miles more fun in the corners! Its also very quiet, probably more so than the factory diff.
I had a Quaife lsd fitted to my older E90 330D (still 320Bhp/700+ Nm) and I have to say the M factory is superior, Overall the car is miles more predictable!
I didn't make my decision based on price either, Just was disappointed with my Quaife last time and fancied a change and had been recommended the M factory from a couple of guys I know who race hondas.

its very sketchy lol...i dont know how one very well known helical type lsd can be so crappy compared to another known helical lsd. and everyone talking about hooking up and no slip is just bullshitting as i have an os giken lsd and it locks...yet i still have traction problems.

i have brand new bridgestone re-11s with powerflex subframe bushings and camber of -0.8 degrees. also i doubt this guy can actually tell a difference in predictability between the 2 lol.

i still dont understand how everyone is really worried about like $200-$300 difference in product that is total probably $2500 for all work including install when it would be much more costly later down the road if it broke.

if you going with helical why not spend the money for the quaife and not worry about much? now if this thing was different and had some special feature and was cheaper that they guarantee then I might consider but there is only so much you can do with helical type.

if you cant afford $300 then this car might not be the car you should be modifying.

I am not sure how you came up with difference of 200-300. They said the pumpkin for welded diff (like most 6MT) will cost 1500 (again that's what they told me in PM). That's 1000 less than what Quaife offers !

I will wait for their group sale when their product comes up for Welded diff. Let's see

Yeah they are in the process of R&D on new bolt on ring gears so you can buy their diff and gear for 1100-1300 (depending on group buys, etc), send you pumpkin to them and they install/rebuild for free. you're at like 1500-1800 for a simple bolt in diff. Compared to the 3500 diff jobs to have the welded ring gear machined off, drilled for bolts, etc etc etc

Just for those who don't know the history of the Helical/Torque Biasing differential, it was invented by Gleason and known as the Torsen (Torque Sensing).

Quaife
History - Reverse engineered the Torsen design (yes, Quaife is a copy) and took out a worthless patent (which has long expired) to make their company look like the almighty and scare away other companies in Europe, and it worked. So much so that 90% of the global population think Quaife invented the Helical LSD.
Function - Torque Biasing, with bias ratio of 2.1:1, which means approx. 66% of torque can be transferred to one wheel
Construction - "Billet" (hate that word, as it is inaccurate. See here) Case & Internal Gears
Warranty - Lifetime warranty in Europe. Other countries depending upon Distributor (i.e if distributor says no, you're out of luck) and sales are region-locked, which means, if you did not purchase from an Authorised distributor in your country, you will not have a warranty. FYI, several of the large BMW Diff Specialists in the US back-door their LSD's from Europe, which means you do not have an official US warranty, and the European trader that broke the territorial sales rules may not assist due to having to keep things under the table. Be wary of this when purchasing a Quaife within the US, as a lot of traders are not even aware of this and just think "lifetime warranty" because it's a Quaife. Non-transferable warranty, so if you did not purchase a brand new unit from an Authorised distributor, again, you will not have a warranty
Guarantee - None

Wavetrac
History - Manufactured by Autotech Driveline, who were the US Quaife Distributor up until around 2007 before they decided to drop Quaife and reverse engineer their own. During 2007 (before the Motovicity changeover), warranty claims were up in the air as Autotech would only warranty parts they had left in stock, therefore a lot of owners got burned
Function - Torque Biasing, with bias ratio of 2.1:1, which means approx. 66% of torque can be transferred to one wheel. However, they do have an additional "centre wave-design" and "friction plates" which pre-load the gears and allow continual power even under no-load conditions (i.e one wheel in the air, or broken axle)
Construction - "Billet" (hate that word, as it is inaccurate. See here) Case & Internal Gears
Warranty - Lifetime warranty worldwide regardless of who you purchased it from (warranty card/sales proof required), as sales are not region-locked and are transferable between owners
Guarantee - None

MFactory
History - We started offering our Helical LSD's in 2007 during the "Quaife Crisis". As with Quaife and Wavetrac before us, we took the Torsen and reversed engineered it to make it better. Our main goal was to simply offer the best value Helical LSD on the market (of which we succeeded)
Function - Torque Biasing, with bias ratio of 2.1:1, which means approx. 66% of torque can be transferred to one wheel
Construction - "Forged" Case & Internal Gears. This is what makes our LSD Stronger, Lighter & Lower Cost than our competition. Others are more expensive because they are "Billet" (i.e inefficient manufacturing when done in bulk) and you are paying "Brand-name Tax"
Warranty - Lifetime warranty worldwide regardless of who you purchased it from (warranty card/sales proof required), as sales are not region-locked and are transferable between owners
Guarantee - 30-day Money Back Guarantee (exc. shipping costs). We want you to be fully satisfied with your new purchase and are the only Manufacturer to offer this

No Load Issue
Yes, under no-load conditions (i.e one wheel in the air, or broken axle) a Helical LSD will act like an open-diff (100% on Quaife/MFactory, 50/50 with the Wavetrac), however, this does not mean that Helical LSD's are bad like proponents of Plate/Clutch style LSD's will tell you. The main market for the Helical LSD is the street car (with occasional track use). Unless you are serious with your circuit/rally racing (not drag racing), 99% of the time you will never be in the situation where you would lift a wheel off the ground, and even if you did, all you need to do is apply a little brake to simulate a loaded-condition and you have power again. And if you break an axle under high speed (like on the drag strip), would you rather your car coast to a stop, or continue to be powered, thus putting you into the wall? In conclusion, for the everyday driver, a Helical LSD is easier and safer to drive (more predictable), maintenance free (fit-and-forget) and, if you ever do get a no-load situation, just apply a little brake with your left foot (no need for special wave designs or friction plates that wear out )

Please Note: The above only applies to our Helical LSD's. For serious track racing (circuit/rally) applications, we very much recommend a Plate type LSD such as the MFactory Metal Plate LSD, Cusco RS LSD or OS Giken (we don't recommend any other brand as the others all use old cone-washer technology and are inferior/obsolete, including the BMW M's and the custom Plate LSD's offered by most BMW Diff Specialists. I'm not saying they are bad, far from it. Just that they are old technology)

Sorry I didn't realise my 1st Post had to be of a certain type! Was looking in the classifieds for a PE exhaust and stumbled across this post.
That aside, there is nothing sketchy about my post, Just giving my 2 cents. Like I said I had birds fit my 330D with a quaife LSD back in 2009, and albeit a different car, I can notice the difference, but who's to say the quaife in a 335 would handle the same as my 330D. My previous car to the 335i was an E63 M6, and in terms of what I know about diffs it may not be a lot as i don't run a race car ( and if I did it would have a plate type diff), however for street driving I have to say that I am as impressed with the M factory as I was when I first started getting to grips with my M6 and its BMW LSD.